Floor edgers, sometimes referred to herein simply as edgers, are used to sand or polish floors in the proximity of vertical structures such as walls and base boards. Edgers operate by rotating an abrasive disc that contacts the floor, wherein the rotating abrasive disc polishes or sands the floor. The abrasive disc typically spins at a high speed, such as 3,200 rpm.
Conventional edgers use brush-type electric motors to spin the abrasive disc. The brush-type motors typically operate at a preselected speed or speeds for a given load. The motors may spin faster than the abrasive disc and a reduction device, such as gears, may be located between the motor and the abrasive disc. For example, a brush-type motor may operate at a speed of 10,000 rpm when no load is applied to the abrasive disc, such as when the abrasive disc is not contacting the floor. However, when the abrasive disc experiences a load, such as contacting a floor, the speed of the motor and, thus, the abrasive disc, typically slows down. Depending on the power of the motor, this slow down may be significant enough to reduce the effectiveness of the edger.
In addition to slowing down the speed of the abrasive disc, the loaded condition of the brush-type motor also may cause the motor to draw more current than it draws at a no-load condition. This additional current draw may cause circuits connected to the edger to exceed limits, which may cause circuit breakers to disconnect the circuits and cut power to the edger. Furthermore, the additional current draw may also present safety issues, such as overheating of the edger and the aforementioned circuits connected to the edger.
Another problem with brush-type motors used in edgers is that they are heavy, which causes the edgers to be heavy. Because edgers operate close to the floor, heavy edgers are difficult to maneuver. The heavy edgers may also cause excessive strain on the users of the edgers because the users typically have to bend over or kneel in order to operate the edgers.